Nginx and Unicorn

Deploy with Nginx and Unicorn

Installing Passenger + Nginx

suppouse the name parent folder is 'deploy':

deploy/
\_ /cenit

Add the new folders

deploy
\_ /cenit
\_ /shared
  \_ /pids
  \_ /sockets
  \_ /log

Inside cenit folder

deploy
\_ /cenit

$ bundle install --deployment --without development test

the project has in Gemfile

gem 'unicorn'  

Open up a blank unicorn.rb document, which will be saved inside config/ directory in your project:

$ vim config/unicorn.rb

Place the below block of code, modifying it as necessary:

# Set your full path to application.
app_dir = File.expand_path('../../', __FILE__)
shared_dir = File.expand_path('../../../shared/', __FILE__)
app_name = "cenit"
 
# Set unicorn options
worker_processes 4
preload_app true
timeout 30
 
GC.respond_to?(:copy_on_write_friendly=) and GC.copy_on_write_friendly = true
 
# Fill path to your app
working_directory app_dir
 
# Set up socket location
listen "#{shared_dir}/sockets/unicorn.#{app_name}.sock", :backlog => 64
 
# Loging
stderr_path "#{shared_dir}/log/unicorn.#{app_name}.stderr.log"
stdout_path "#{shared_dir}/log/unicorn.#{app_name}.stdout.log"
 
# Set master PID location
pid "#{shared_dir}/pids/unicorn.#{app_name}.pid"
 
before_fork do |server, worker|
  defined?(ActiveRecord::Base) and ActiveRecord::Base.connection.disconnect!
  old_pid = "#{server.config[:pid]}.oldbin"
  if File.exists?(old_pid) && server.pid != old_pid
    begin
      sig = (worker.nr + 1) >= server.worker_processes ? :QUIT : :TTOU
      Process.kill(sig, File.read(old_pid).to_i)
    rescue Errno::ENOENT, Errno::ESRCH
      # someone else did our job for us
    end
  end
end
 
after_fork do |server, worker|
  defined?(Rails) and Rails.cache.respond_to?(:reconnect) and Rails.cache.reconnect
end
 
before_exec do |server|
  ENV['BUNDLE_GEMFILE'] = "#{app_dir}/Gemfile"
end

$ rake assets:precompile RAILS_ENV=production RACK_ENV=production

$ rake db:migrate RAILS_ENV=production RACK_ENV=production

Create unicorn init script with app name (optional)

$ sudo vi /etc/init.d/cenit

note: field with BOLD need to be changed

#!/bin/sh

### BEGIN INIT INFO
# Provides:          unicorn
# Required-Start:    $all
# Required-Stop:     $all
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: starts the unicorn app server
# Description:       starts unicorn using start-stop-daemon
### END INIT INFO

set -e

USAGE="Usage: $0 "

# app settings
USER="deploy"
APP_NAME="appname"
APP_ROOT="/home/$USER/$APP_NAME"
ENV="production"

# environment settings
PATH="/home/$USER/.rbenv/shims:/home/$USER/.rbenv/bin:$PATH"
CMD="cd $APP_ROOT && bundle exec unicorn -c config/unicorn.rb -E $ENV -D"
PID="$APP_ROOT/shared/pids/unicorn.pid"
OLD_PID="$PID.oldbin"

# make sure the app exists
cd $APP_ROOT || exit 1

sig () {
  test -s "$PID" && kill -$1 `cat $PID`
}

oldsig () {
  test -s $OLD_PID && kill -$1 `cat $OLD_PID`
}

case $1 in
  start)
    sig 0 && echo >&2 "Already running" && exit 0
    echo "Starting $APP_NAME"
    su - $USER -c "$CMD"
    ;;
  stop)
    echo "Stopping $APP_NAME"
    sig QUIT && exit 0
    echo >&2 "Not running"
    ;;
  force-stop)
    echo "Force stopping $APP_NAME"
    sig TERM && exit 0
    echo >&2 "Not running"
    ;;
  restart|reload|upgrade)
    sig USR2 && echo "reloaded $APP_NAME" && exit 0
    echo >&2 "Couldn't reload, starting '$CMD' instead"
    $CMD
    ;;
  rotate)
    sig USR1 && echo rotated logs OK && exit 0
    echo >&2 "Couldn't rotate logs" && exit 1
    ;;
  *)
    echo >&2 $USAGE
    exit 1
    ;;
esac

$ sudo chmod 755 /etc/init.d/cenit
$ sudo update-rc.d cenit defaults

Test service

$ sudo service cenit start  
$ sudo service cenit stop

Configuring NGNIX

$ cd /etc/nginx/sites-available

$ vim default 

and the copy the next specification:

upstream cenit {
    # Path to Unicorn SOCK file
    server unix:/home/ubuntu/deploy/shared/sockets/unicorn.cenit.sock fail_timeout=0;
}

server {
    # Application root, as defined previously
    root /home/ubuntu/deploy/cenit/public;

    listen  80;
    server_name localhost;

    try_files $uri/index.html $uri @cenit;

    access_log /var/log/nginx/cenit_access.log combined;
    error_log /var/log/nginx/cenit_error.log;

    location @cenit {
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header Host $http_host;
        proxy_redirect off;
        proxy_pass http://cenit;
    }

    error_page 500 502 503 504 /500.html;
    client_max_body_size 4G;
    keepalive_timeout 10;
}

restart nginx server

$ sudo service nginx restart

if you did not use the optional step above you can run :

$ bundle exec unicorn_rails -c config/unicorn.rb -D

If you have some trouble with secret_key_base, you can generate a random secret key value:

$ rake secret

Then take this value and put it in config/initializers/secret_token.rb:

Cenit::Application.config.secret_key_base = 'bla' # replace this